Viscosity and flow control valve



June 4, 1963 R. B. PLASS 3,092,146

VISCOSITY AND FLOW CONTROL VALVE Filed March 13, 1961 INVENTOR. RA YM0/V05PLA 55 JM b4 3% TTUR/VEYS United States Patent 3,092,146 VISCGSHTY AND FLOW CONTROL VALVE Raymond B. Plass, Piedmont, Califl, assignor to Ray 0i! Burner (30., San Francisco, Calif., a corporation of Nevada Filed Mar. 13, 1961, Ser- No. 95,292. 2 Claims. (Cl. 137-62-5.47)

This invention relates to burner controls for oil burners or the like which are sensitive to variations in viscosity of the liquid which passes through them and to valves of the general type and function as that disclosed in my Patent No. 2,597,177, entitled Adjustable Viscosity Sensitive Burner Control.

As described in the above mentioned patent, viscosity sensitive valves are employed in systems where a constant volume pump directs oil toward an oil burner and the rate of burning or volume of oil delivered to the burner is controlled by bypassing a given quantity of the constant volume pump output back to the source of sup ply. In order to avoid variation in flame rate at the burner because of variations in viscosity of the oil as it is being delivered thereto viscosity controls in the form of Poiseuille tubes are interposed in the burner supply line and the bypass line to maintain a constant ratio of flow through these tube lines regardless of variations in viscosity. The patent referred to above relates to a viscosity sensitive valve which is capable of being adjusted to vary flow through the two Poiseuille tubes and thereby vary the flame rate at the burner without the necessity of employing an additional bypass valve. The present application relates to such an adjustable viscosity valve employing the Poiseuille effect.

It is the object of the present invention to provide a viscosity and flow control valve which is simpler in construction and operation than that of the patent above mentioned as well as others designed for this purpose.

Still further and more specific objects and advantages of the invention are made apparent in the following specification by reference to the accompanying drawing wherein a preferred form of the invention is illustrated in detail.

In the drawing:

FIG. 1 is a schematic view of a burner control system embodying the present invention; and

FIG. 2 is a sectional view taken on the line II-Il of FIG. 1.

The burner control system illustrated schematically in FIG. 1 comprises a burner tip which is disposed in the fire box of a furnace or the like (not shown) and to which oil and air are delivered in a conventional manner to produce a combustible mixture. The rate of flow of oil to the burner tip 10 determines the size of the flame in the fire box and the present invention is concerned with controlling and adjusting this rate and particularly with improved means for accomplishing this purpose, it being desirable to maintain a constant rate of burning for any given setting. The oil consumed at the burner is supplied from a source (not shown) through a pipe 11 being withdrawn therefrom and delivered by a pump 12 to the interior of a reservoir 13. An overflow tube 14- communicates between the reservoir and the source of supply to prevent the build-up of excessive pressure in the reservoir. A pump 15, of the positive displacement constant volume type, also disposed in the reservoir is employed for the purpose of supplying oil to the burner tip. 10. A viscosity and rate control valve generally indicated at 16 receives oil from the pump through a line 17 and functions to direct a part of the output of the pump 15 to the burner 10 and to bypass the remainder back to the reservoir 13 and thence if necessary through the return line 14 to the source of supply.

Patented June 4, 1963 ice The capacity of the pump 15 exceeds the maximum requirements of the burner 10 so that a portion of the oil flows toward the burner while the remainder is returned to the reservoir 13.

While the viscosity valve shown in my prior patent hereinabove referred to employed two tapered conical passages with conical plugs therein to provide two paths of substantially constant length but with variable cross sections by reasons of adjustability of the plugs in the passages, the present invention provides a greatly simplified viscosity valve in the form of a disc 19 fitting and rotatable in an annular cavity in a housing portion 20' of the valve structure generally indicated at 16. The line 17 from the pump 15 communicates with the valve cavity through a passage 21 and outlet passages equally spaced on opposite sides of the passage 21 are provided at 22 and 23. The disc 19 has a groove 24, see also FIG. 2, formed eccentrically in its peripheral surface so as to extend a greater part of the Way around the disc and communicate simultaneously with the passages 21, 22 and 23. Therefore with the disc in a position centering its groove with the inlet passage 21, two passages of equal length and of diminishing cross section are present be tween the inlet passage 21 and the two outlet passages 22 and 23. While these paths remain of equal length, their cross section can be varied by adjustment of the disc by means of a lever 26 connected externally of the housing 20 with a rotatable shaft 27 upon which the disc 19 is fixedv Thus by rotation or angular adjustment of the disc, the ratio of the volume of oil flowing through the outlet passage 22 and a passage 27 to the reservoir 13, and the volume of oil flowing from the outlet passage 23 and through a line 28 to the burner 10 may be varied for controlling the rate of flow at the burner. Though it is not contemplated in ordinary operation that the disc 19 will be adjusted to completely close the inlet 1, a relief valve 30 will relieve the pressure of pump 15 back to the reservoir should this occur.

As shown in the drawing, the passage 21 is considerably larger in cross sectional area than the groove 24 even at its central area or point of greatest depth. Thus for a given flow rate, the pressure drop through the passage 21 and its point of entrance into the groove 24 is much less than the pressure drop through the groove 24 from its inlet to either of its outlets. This is necessary to obtain the benefits of the Poiseuille phenomenon since an inlet passage of smaller cross section than the tapered groove would result in an increased pressure drop which would then be a controlling factor reducing the control elfect of the tapered groove. Turbulence would also be caused by a small inlet passage which would be detrimental to the desired viscous flow control in the tapered passages.

It is possible that upon changing the rate of flow to the burner that different conditions of back pressure will exist in the discharge passages 22 and 23 and affect the accuracy of the viscosity sensitive control valve. To compensate for this and to maintain equal pressures in the discharge passages 22 and 23 irrespective of the position of the disc 19' a pressure balancing valve is provided adjacent these passages comprising a free floating piston 31 in a cylindrical bore 32 formed in the housing and intercepting passages 22-27 and passages 2328. A plug 34 closes one end of the bore 32 so that the spaces at the ends of the piston 31 and the relationship of the passages at opposite ends of the piston are symmetrical. Consequently in the event of unequal pressures occurring adjacent the discharge ports of the viscosity sensitive valve, the pressures will immediately be equalized by action' of the free floating piston 31. For example if the pressure at the discharge passage 22 exceeds that of the pressure at the discharge passage 23, it will bias the piston 31 to a position where it closes or partially closes the line 28 causing a build up of pressure in the discharge 23 until the discharge pressures are equalized.

The structure illustrated, wherein the viscosity sensitive control including the disc 19 and the pressure balancing valve including the piston 31 are all included in a Single casting, provides a very simple and inexpensive construction which is positive and dependable in operation.

I claim:

1. A viscosity valve of the kind described comprising a valve body with a cylindrical cavity having an inlet in its cylindrical wall and two outlets therein at equal distances from opposite sides of the inlet, a disc substantially filling and rotatable in said cavity, said disc having a groove in its peripheral surface forming a tapered passage between the inlet and both of the outlets, and means to rotate the disc, said inlet being of substantially greater cross sectional area than said groove at its point of greatest cross section.

2. A viscosity valve of the kind described comprising a valve body with a cylindrical cavity having an inlet in its cylindrical wall and two outlets therein at equal distances from opposite sides of the inlet, a disc substantially filling and rotatable in said cavity, said disc having a peripheral groove formed eccentrically of itself and sufficiently long to communicate with the inlet and both outlots to form two passages which taper between the inlet and the outlets, and means to rotate the disc to vary the flow capacity of said passages, said inlets and outlets at their points of communication with said groove being sufficiently large with respect to the size of the groove and so arranged that restriction to flow will occur principally in the groove and will be negligible at said points of communication.

References Cited in the file of this patent UNITED STATES PATENTS 1,493,133 Sykora May 6, 1924 1,993,790 Kinsella May 12, 1935 2,067,346 Rovinsky Jan. 12, 1937 2,597,177 Plass May 20, 1952 

1. A VISCOSITY VALVE OF THE KIND DESCRIBED COMPRISING A VALVE BODY WITH A CYLINDRICAL CAVITY HAVING AN INLET IN ITS CYLINDRICAL WALL AND TWO OUTLETS THEREIN AT EQUAL DISTANCES FROM OPPOSITE SIDES OF THE INLET, A DISC SUBSTANTIALLY FILLING AND ROTATABLE IN SAID CAVITY, SAID DISC HAVING A GROOVE IN ITS PERIPHERAL SURFACE FORMING A TAPERED PASSAGE BETWEEN THE INLET AND BOTH OF THE OUTLETS, AND MEANS TO ROTATE THE DISC, SAID INLET BEING OF SUBSTANTIALLY GREATER CROSS SECTIONAL AREA THAN SAID GROOVE AT ITS POINT OF GREATEST CROSS SECTION. 